Petroleum deposits are found throughout the world. In some places, such as in Alberta and Saskatchewan, Canada, oil sands contain large petroleum deposits. In Alberta, the oil sands are generally found in three regions, namely, the Athabasca, Peace River and Cold Lake regions, and cover a total of nearly 34.6 million acres. Alberta has a large-scale commercial industry devoted to recovering and processing oil sands.
The oil sands of Alberta and Saskatchewan may generally comprise approximately 10-12 percent bitumen, 80-85 percent mineral matter and 4-6 percent water. Thus, producing one barrel of oil may require digging up, moving and processing more than two tons of oil sand. Processed sand may then be returned to the recovery site for site reclamation.
Bitumen is a heavy, sticky, black viscous oil. At room temperature, bitumen's viscosity is not unlike that of cold molasses. Bitumen will generally not flow unless heated or diluted with lighter hydrocarbons. In comparison to conventional crude oil, which generally flows naturally or may be pumped from the ground, bitumen generally must be recovered in situ, or “in place.” In situ recovery down to about 250 feet may be accomplished by open-pit mining. For example, bitumen recovery in the Athabasca region near Fort McMurray, Alberta, involves some of the world's largest trucks and shovels. Deeper bitumen deposits may require use of other techniques that reduce bitumen viscosity by heat or introduction of solvents.
Such techniques may include cyclic steam stimulation (CSS), which relies on high-pressure steam injected into the oil sand deposit. The heat softens the oil sand and the water vapor helps break the bitumen apart from the sand. For example, at Cold Lake, oil sands deposits may be heated by steam injection to bring bitumen to the surface, and then diluted with condensate for shipping by pipelines. Steam-assisted gravity drainage (SAGD), uses two horizontal wells, one several yards above the other. Low pressure steam is injected into the upper wellbore, thus heating the bitumen and reducing its viscosity to cause it to drain into the lower wellbore, where it is pumped out. In situ combustion (ISC, or “fireflooding”), such as toe-to-heel air injection, essentially burns some of the heavy oil in place to create a combustion zone that moves through the oil formation toward the production wells. Electro-thermal dynamic stripping process (ET-DSP), uses electricity to heat oil sands deposits to reduce bitumen viscosity, thus allowing production using simple vertical wells. Vapour recovery extraction (VAPEX), uses solvents rather than steam to displace oil and reduce bitumen viscosity. Other production techniques may include cold heavy oil production with sand (CHOPS), pressure pulsing techniques (PPT), inert gas injection (IGI), and various hybrids.
Once recovered, bitumen may be processed into an upgraded crude oil before it is transported and further refined to gasoline, diesel fuels, and other petroleum products. Bitumen processors may thus be located in close proximity to the in situ mining operation. Bitumen upgraders may be massive industrial complexes—for example, covering 1,000 acres or more—that may require, among other things, vast amounts of piping, large pressure vessels, heaters, pumping stations, holding tanks, metering devices, and blending facilities.
Bitumen processing plants may be “stick-built,” or constructed from the ground up at the oil sands location on which they will operate. However, disadvantages to stick-built construction may include exposure to extreme adverse weather conditions, no local labor force, poor quality control, poor productivity, lack of existing transportation infrastructure, lack of existing utilities infrastructure, high material transportation costs, and inadequate raw material storage, and lack of existing human services and support infrastructure.
Alternatively, bitumen processing plants may be partially constructed from sub-assemblies or modules, e.g., pipe rack, process and/or equipment modules, that are fabricated, assembled and/or tested off-site, and transported to the heavy industrial plant site. A single large-scale bitumen processing plant may require the fabrication of several hundred to more than 1,000 modules. The modules may then be individually transported to the processing plant site for assembly. Because of the inland location of the Alberta oil sands, modules may be moved by land or marine transportation. Marine transportation, however, is extremely limited in that only certain processing plants have river access, and river access is blocked for much of the year by ice. Thus, modules are manufactured in significant population centers nearest the processing plants sites, namely, Fort McMurray and Edmonton. Although such towns provide some needed infrastructure, many of the disadvantages of stick-built construction nevertheless remain with module construction in such nearby industrial centers. Furthermore, by concentrating module fabrication and assembly in nearby population centers, additional disadvantages arise, such as exacerbated labor shortages, inflated labor costs due to scarce resources, outdoor module assembly in severe adverse weather, and exposure of town economics to single-industry job volatility.
Thus, there is a need for more efficient method and system of providing modules for assembly at a heavy industrial hydrocarbon processing plant site.